There will be a few hundred Enfield owners and collectors sighing and agreeing with you 303t. It's important that some of these little 'non-guns' survive but nobody seems to know what they are. Well, we do.....non-guns, but there isn't a classification on a licence for non guns.
It would take a registered dealer to get one up to the proof house, get it 'not capable of being proofed', get a statement of its condition from a totally independent graduate engineer - preferably someone involved in the original programme, together with the original drawings, THEN sell it on to a collectot.
Then and IF the muck hit the proverbial fan, let them take you on. They very probably wouldn't bother but if they were so foolhardy as to do so they'd loose of course, THEN ask for total costs against them for being so foolhardy